According to the http://www.creationkit.com/SM_Event_Node, there is a known issue with Story manager event nodes: "If two mods both modify an event node for some quest in the mods, only the quest belonging to the last loaded mod will be started. This occurs even if you create a duplicate SM Event and enter only your quests."

I think I'm probably misunderstanding what this means, and would be grateful for any clarification. In my mod I want to use several of the OnStoryXXXX events, so I add a stacked (shares event) quest node to the stacked event node: kill actor node, and start my quest from there. I made an additional test mod that did the same, and ran Skyrim with both mods enabled, and both mods' quests fire properly when I kill an actor. What have I missed?

I think it means if you mod a vanilla event node quest, not if you add your own.

Uh, that's a nasty one. I can see them having trouble with that. I don't have the CK now with me to test myself but just a few ideas:
So...in the Object Tree you open a SM Event Node and add a quest there. Unfortunately I can see the issue happening if two mods add something to the same node.
BUT you can add a New SM Event Node from the Object Tree then select the event type for it. I wonder if there will still be issues that way.
Now from what I remember vanilla has an Event Node for each event type even if not used (not starting any vanilla quest). I added once such a node and I believe I was able to select a small number of event types from the possible ones. This could be a problem even if it works with a new Event Node but wiki says you'll still have the initial problem.
Edit: I truly hope wiki is referring about creating a new group (branches) for quests in the same SM Event Node, not about creating a new node from the Object Window.

Basically all it means is that all your sm event node stuff needs to be in one plugin. I hadn't read the issue, had two sm events in separate plugins leading to one not working, realized the problem and put them in the same mod.

Oh, aha, thanks, I think I get it. I was taking the 'Kill actor' event node as a vanilla event node, that I was modifying. But I think it really applies only to changing quest nodes (presumably either directly or by changing their branch parentage, i.e. the conditions under which they start). That would make sense, and explain why no one else seemed to be as horrified by this as I was.

No, done that, seems to be fine - unless I'm missing something.

But the problem would be if someone else's mod clashed with that, because they'd altered the same nodes. I'm hoping this is only true if one changes (rather than just adding) existing quest nodes, though.

Indeed, its a compatibility issue.

Unfortunately, I have heard that adding new quest nodes still causes a compatibility problem. Don't quote me, I could be wrong. Basically my understanding is that any modification to an SM Event Node (modifying an existing branch to add your quest, or adding a new quest node to put your quest in) would lead to compatibility issues if another mod did the same. Would love some confirmation.

Oh dear.

But I have tried adding two OnStoryKillActor quests in one mod, a third in a second mod, and fourth in a third mod, and all four quests are launched as they should be. So it can't be quite as simple as the wiki suggests, at least.

This is good news if true! Each mod added a new quest node inside the same SM Event Node?

Yes. The first mod created a stacked quest node (under KillActor) - the second and third independently added quests to it.


And I tried setting Num quests to run to 2 in my third quest, thinking it might mess things up: all four quests still ran.

"added quests to it" means to the staked quest node or to the SM node? Did you have the first mod loaded in CK while saving the 2nd/3rd one?

Hm, bit long ago for me to be sure of all the details now, but I did try quite a few ways. I know that I tested it first with two different mods that were quite independent (not loaded in the CK at the same time), and secondly with one mod always loaded and two secondary mods (not loaded at the same time as each other). But I think that in the second case I may have added new quest nodes to the stacked branch node created by the always-loaded mod, rather than merely adding quests to a quest node created there. I think I must test some more

Did it again, just adding a quest in mod2 to the new quest node (with a quest) created in mod1. Both quests still run.

I'm not sure whether there is a bug, or whether any problem is down to how "good a citizen" you - and any other modder who was added to an Event Node - has been.

I think this is a Shared/Not-Shared problem?

1. If any quest in the tree - which is NOT ticked for sharing - is higher than your Quest/Node; your Quest will not fire (because the unshared one nicked the event data)
2. And the opposite - If you make an unshared node, you may be steeling other Nodes data under that same SM Event (which are lower in the tree than yours).

AND - because you cannot know which will appear "first" in the tree, when independant mods are loaded, there is no way to comply with the "make sure yours is highest" fix ... So unless everyone is "a good citizen" compatability issues abound ...

As Ingenue says, though, (much) more testing is needed.

Right. All my quest nodes have had Shares Event set.

There is obviously a lot of scope for fouling things up for other quests by changing the event node hierarchy/conditions, as well.

hmm...so all this is about the "Shares event" check? That one was pretty clear to me (not fully tested by myself but clear that you have to check that in some situations).
I thought the problem was a CK issue, not a modder issue, that two mods modify the same record which in this case is the SM Node itself thous in your game the node will look like in the last loaded mod.

Well, you can:

• add Quest Node A - and then add Quest-A to that - to the Script Event Node in Mod-AAA
  
• add Quest Node B - and then add Quest-B to that - to the Script Event Node in Mod-BBB

And both quests will fire and run fine

(I have not tested without shared checked, I have not tested adding Quest B from Mod-B to Quest Node A and probably some other combinations too)

So, it would appear that two different mods, adding two quest nodes - with one quest each - to the same SM Event Node (or the script event one, at least) does work OK (so long as they have shared, ticked).

So, if an issue does exist? I wonder whether one of the other Main Event Nodes is not properly Shared?

(Or am I just not understanding the problem? Which is probably more likely )

Great. Thanks for testing this too. I am going to remove the "known issue" section from the wiki, since it looks like Shares event was probably responsible.